The present invention relates to an improved bottle, and, more particularly, to a large capacity molded plastic bottle of the type used to store water which is dispensed from an appropriate dispensing apparatus. The bottle of the present invention exhibits increased strength and is simultaneously more readily stackable as an aid to convenient storage.
Stackable blow-molded, large capacity plastic water bottles are known. U.S. Pat. No. 4,308,955 discloses an inter-fitting, stackable bottle made of blow-molded plastic in which water is stored for appropriate dispensing. The bottle has a rectangular cross-section taken perpendicularly to its major axis and includes a locking projection or tenon on one face thereof and a socket or mortise on an opposed face. The bottle also includes alternating ribs and indentations spaced along its major axis for strengthening the walls thereof.
To store the above prior art bottle, a first bottle is placed on a support surface or floor with its socket or mortise down and its projection or tenon pointing upwardly. A second similar bottle to be stacked on top of the first bottle is positioned so that the projection of the first bottle fits into the socket of the second bottle to horizontally locate and stabilized the stack of bottles. The weight of the superjacent bottle is carried by the engagement between the abutting surfaces or faces of the bottles.
Water bottles having circular cross-sections are also known. Typically, such bottles may be formed with similar strengthening ribs and indentations, but are typically not interlocking. Because of the around circumference of such bottles, maintaining them in a vertical stack typically requires that each bottle be held in an individual square or rectangular carton or case with the cartons or cases being vertically stacked.
The expense of fabricating and using cases for circular cross-section bottles render them somewhat inconvenient. This inconvenience was apparently one of the primary motivations for devising the rectangular cross-section bottle. Rectangular cross-section bottles may be vertically stacked, as noted above and with the projections and sockets being present a stack of such bottles is horizontally stable. Thus, the rectangular cross-section bottles exhibit an improvement relative to stackability over circular cross-section bottles and eliminate the need for cartons and cases.
Circular cross-section bottles exhibit another disadvantage. Specifically, because lateral contact of such bottles with a flat surface, or with the surface of a subjacent or superjacent bottle, results in line contact along the surface of the bottle parallel to its major axis, a high concentration of forces exists along the line when the bottles are full of water. Resting such a bottle on a surface, let alone dropping the bottle on the surface, accordingly, results in large deflections of the bottle's wall and the concomitant generation of extremely high forces and pressures within the bottle. The possibility of these high pressures and forces often results in leakage through the snap-on type of cap normally closing such bottles. These high forces and pressure may also force the snap-on cap from the bottle with a concomitant spillage of the water therein. This may result in the need to use a more leak-proof closure, such as screw-on cap. The production of such a cap and the need for the bottle neck to include a mating thread are cost-increasing factors.
Bottles with rectangular cross-sections may avoid, to some extent, the leakage and spillage problems attending the use of circular cross-section bottles closed with snap-on caps. However, although many prior art circular cross-section bottles hold about 5 gallons of water and weigh about 42.2 pounds (plus bottle weight) when filled, rectangular cross-section bottles typically hold 6 gallons and thus, weigh about 50.6 pounds (plus bottle weight) when filled. When stacked three- or four-high, the bottom rectangular cross-section bottle experiences a load of more than about 100-150 pounds. These loads have been found to result in leakage or snap-on cap dislodgement similar to that experienced with smaller capacity circular cross-section bottles. Thus, the forces and pressures within these bottle generated by wall deflection-caused contact of the bottle with a surface (or dropping of the bottle onto the surface) can force off a cap other than a screw cap or other special cap, again resulting in leakage and/or spillage.
An object of the present invention is the provision of a bottle which eliminates the disadvantages of the foregoing prior art bottles and which is convenient to use and inexpensive to manufacture.
Further objects of the present invention are the provision of a plastic, blow-molded bottle which may be sealed with a simple inexpensive snap-cap, which is stackable and which is aesthetically pleasing.